import os
import sys
from typing import List

from django.core.management.base import AppCommand

from django_extensions.management.utils import _make_writeable, signalcommand


class Command(AppCommand):
    help = "Creates a Django template tags directory structure for the given app name "
    "in the apps's directory"

    def add_arguments(self, parser):
        super().add_arguments(parser)
        parser.add_argument(
            "--name",
            "-n",
            action="store",
            dest="tag_library_name",
            default="appname_tags",
            help="The name to use for the template tag base name. "
            "Defaults to `appname`_tags.",
        )

    requires_system_checks: List[str] = []
    # Can't import settings during this command, because they haven't
    # necessarily been created.
    can_import_settings = True

    @signalcommand
    def handle_app_config(self, app_config, **options):
        app_dir = app_config.path
        tag_library_name = options["tag_library_name"]
        if tag_library_name == "appname_tags":
            tag_library_name = "%s_tags" % os.path.basename(app_dir)
        copy_template("template_tags_template", app_dir, tag_library_name)


def copy_template(template_name, copy_to, tag_library_name):
    """Copy the specified template directory to the copy_to location"""
    import django_extensions
    import shutil

    template_dir = os.path.join(django_extensions.__path__[0], "conf", template_name)

    # walk the template structure and copies it
    for d, subdirs, files in os.walk(template_dir):
        relative_dir = d[len(template_dir) + 1 :]
        if relative_dir and not os.path.exists(os.path.join(copy_to, relative_dir)):
            os.mkdir(os.path.join(copy_to, relative_dir))
        for i, subdir in enumerate(subdirs):
            if subdir.startswith("."):
                del subdirs[i]
        for f in files:
            if f.endswith(".pyc") or f.startswith(".DS_Store"):
                continue
            path_old = os.path.join(d, f)
            path_new = os.path.join(
                copy_to, relative_dir, f.replace("sample", tag_library_name)
            )
            if os.path.exists(path_new):
                path_new = os.path.join(copy_to, relative_dir, f)
                if os.path.exists(path_new):
                    continue
            path_new = path_new.rstrip(".tmpl")
            fp_old = open(path_old, "r")
            fp_new = open(path_new, "w")
            fp_new.write(fp_old.read())
            fp_old.close()
            fp_new.close()
            try:
                shutil.copymode(path_old, path_new)
                _make_writeable(path_new)
            except OSError:
                sys.stderr.write(
                    "Notice: Couldn't set permission bits on %s. You're probably using an uncommon filesystem setup. No problem.\n"  # noqa: E501
                    % path_new
                )
